Update emulator to the latest version, switch to API 28

This commit updates the Android emulator to the latest version
available (`4969155` a.k.a. v27.3.10), switches its system image to API 28,
makes sure that the emulator is started from the `emulator` subdir of the
Android SDK root (the binary in `tools` won't work anymore) and makes sure we
don't error out when we attempt to uninstall packages that don't exist in the
AVD.

In addition to those changes, two new properties were added to the
`CreateAndroidEmulator` task:

    * `RamSizeMB` (defaults to `2048`)
       Allows to set the emulator's RAM size
    * `DataPartitionSizeMB` (defaults to `2048`)
       Allows to set the emulator's data partition size. The data partition
       cretaed by default has only around 800MB of space available which may not
       be enough to install and run all our tests.

Author: grendello

Configuration.props

@@ -116,7 +116,7 @@
     <AndroidToolPath Condition=" '$(AndroidToolPath)' == '' ">$(AndroidSdkFullPath)\tools</AndroidToolPath>
     <AndroidToolsBinPath Condition=" '$(AndroidToolsBinPath)' == '' ">$(AndroidToolPath)\bin</AndroidToolsBinPath>
     <AndroidToolExe Condition=" '$(AndroidToolExe)' == '' ">android</AndroidToolExe>
-    <EmulatorToolPath Condition=" '$(EmulatorToolPath)' == '' ">$(AndroidSdkFullPath)\tools</EmulatorToolPath>
+    <EmulatorToolPath Condition=" '$(EmulatorToolPath)' == '' ">$(AndroidSdkFullPath)\emulator</EmulatorToolPath>
     <EmulatorToolExe Condition=" '$(EmulatorToolExe)' == '' ">emulator</EmulatorToolExe>
     <NdkBuildPath Condition=" '$(NdkBuildPath)' == '' And '$(HostOS)' != 'Windows' ">$(AndroidNdkDirectory)\ndk-build</NdkBuildPath>
     <NdkBuildPath Condition=" '$(NdkBuildPath)' == '' And '$(HostOS)' == 'Windows' ">$(AndroidNdkDirectory)\ndk-build.cmd</NdkBuildPath>

build-tools/Xamarin.Android.Tools.BootstrapTasks/Xamarin.Android.Tools.BootstrapTasks/Adb.cs

@@ -59,7 +59,7 @@ protected override string GenerateCommandLineCommands ()
 
 		protected override void LogEventsFromTextOutput (string singleLine, MessageImportance messageImportance)
 		{
-			base.LogEventsFromTextOutput (singleLine, messageImportance);
+			Log.LogMessage (MessageImportance.Low, singleLine);
 			Lines.Add (singleLine);
 		}
 	}

build-tools/Xamarin.Android.Tools.BootstrapTasks/Xamarin.Android.Tools.BootstrapTasks/CreateAndroidEmulator.cs

@@ -22,7 +22,10 @@ public class CreateAndroidEmulator : Task
 
 		public                  string          TargetId        {get; set;}
 
-		public                  string          ImageName       {get; set;} = "XamarinAndroidTestRunner";
+		public                  string          ImageName           {get; set;} = "XamarinAndroidTestRunner";
+		public                  string          RamSizeMB           {get; set;} = "2048";
+		public                  string          DataPartitionSizeMB { get; set;} = "2048";
+
 
 		public override bool Execute ()
 		{
@@ -68,6 +71,29 @@ void Run (string android)
 
 			var arguments   = $"create avd --abi {AndroidAbi} -f -n {ImageName} --package \"{TargetId}\"";
 			Exec (android, arguments);
+
+			string configPath = Path.Combine (Environment.GetFolderPath (Environment.SpecialFolder.Personal), ".android", "avd", $"{ImageName}.avd", "config.ini");
+			if (!File.Exists (configPath)) {
+				Log.LogWarning ($"Config file for AVD '{ImageName}' not found at {configPath}");
+				Log.LogWarning ($"AVD '{ImageName}' will use default emulator settings (memory and data partition size)");
+				return;
+			}
+
+			ulong diskSize;
+			if (!UInt64.TryParse (DataPartitionSizeMB, out diskSize))
+				Log.LogError ($"Invalid data partition size '{DataPartitionSizeMB}' - must be a positive integer value expressing size in megabytes");
+
+			ulong ramSize;
+			if (!UInt64.TryParse (RamSizeMB, out ramSize))
+				Log.LogError ($"Invalid RAM size '{RamSizeMB}' - must be a positive integer value expressing size in megabytes");
+
+			if (Log.HasLoggedErrors)
+				return;
+
+			File.AppendAllLines (configPath, new string[] {
+				$"disk.dataPartition.size={diskSize}M",
+				$"hw.ramSize={ramSize}"
+			});
 		}
 
 		StreamWriter stdin;

build-tools/android-toolchain/android-toolchain.projitems

@@ -23,7 +23,7 @@
       <HostOS>Linux</HostOS>
       <DestDir>tools</DestDir>
     </AndroidSdkItem>
-    <AndroidSdkItem Include="emulator-linux-4266726">
+    <AndroidSdkItem Include="emulator-linux-4969155">
       <HostOS>Linux</HostOS>
       <DestDir>emulator</DestDir>
     </AndroidSdkItem>
@@ -42,7 +42,7 @@
       <HostOS>Darwin</HostOS>
       <DestDir>tools</DestDir>
     </AndroidSdkItem>
-    <AndroidSdkItem Include="emulator-darwin-4266726">
+    <AndroidSdkItem Include="emulator-darwin-4969155">
       <HostOS>Darwin</HostOS>
       <DestDir>emulator</DestDir>
     </AndroidSdkItem>
@@ -61,7 +61,7 @@
       <HostOS>Windows</HostOS>
       <DestDir>tools</DestDir>
     </AndroidSdkItem>
-    <AndroidSdkItem Include="emulator-windows-4266726">
+    <AndroidSdkItem Include="emulator-windows-4969155">
       <HostOS>Windows</HostOS>
       <DestDir>emulator</DestDir>
     </AndroidSdkItem>
@@ -151,10 +151,10 @@
       <HostOS></HostOS>
       <DestDir>extras\android\m2repository</DestDir>
     </AndroidSdkItem>
-    <AndroidSdkItem Include="x86-21_r05">
+    <AndroidSdkItem Include="x86-28_r04">
       <HostOS></HostOS>
       <RelUrl>sys-img/android/</RelUrl>
-      <DestDir>system-images\android-21\default\x86</DestDir>
+      <DestDir>system-images\android-28\default\x86</DestDir>
     </AndroidSdkItem>
   </ItemGroup>
   <ItemGroup>

build-tools/scripts/TestApks.targets

@@ -32,10 +32,12 @@
         AndroidAbi="x86"
         AndroidSdkHome="$(AndroidSdkDirectory)"
         JavaSdkHome="$(JavaSdkDirectory)"
-        SdkVersion="21"
+        SdkVersion="28"
         ImageName="$(_TestImageName)"
         ToolExe="$(AvdManagerToolExe)"
         ToolPath="$(AndroidToolsBinPath)"
+        RamSizeMB="2048"
+        DataPartitionSizeMB="2048"
     />
     <StartAndroidEmulator
         Condition=" '$(_ValidAdbTarget)' != 'True' "